Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in the application and are not admitted to be prior art by inclusion in this section.
Modern processors are products of iterative scale down of fabrication processes. Smaller fabrication processes have allowed more transistors to be inserted to a similar surface area compared to a processor produced by a previous fabrication process. Additional transistors have allowed modern processors to provide additional computation capacity using a similar power envelope compared to a previous generation processor.
A larger share of power consumption in modern processors is caused by leakage current. Increased leakage current is a byproduct of continued shrinkage of gate dimensions associated with the modern processors. Leakage current was irrelevant to power usage at 1 micron gates used in legacy fabrication processes. A third of the power usage was consumed by leakage current at fabrication processes that used 180 nm gates. In modern processors that are built using fabrication processes that use 65 nm gates or below, leakage current may exceed power used by computation. In addition, the leakage current variability has also increased dramatically in modern processors.